FS-7720 improve play_and_detect_speech to set current_application_response channel variable as follows:
"USAGE ERROR": bad application arguments
"GRAMMAR ERROR": speech recognizer failed to load grammar
"ASR INIT ERROR": speech recognizer failed to allocate a session
"ERROR": any other errors
This is useful for determining that play_and_detect_speech failed because the recognizer is out of licenses
giving the developer a chance to fall back to traditional DTMF menu navigation.